Category Archives: Linux

I’ve recently been experimenting with using a seedbox; I built one using CentOS 6.5 and Deluge. The original guide I followed used a repo that only had Deluge 1.3.5 and later through some googling I found a repo for installing 1.3.6.

For a while I always wondered why fail2ban sometimes put in the same rule twice under iptables:

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[root@localhost~]# iptables -L

Chain INPUT(policy ACCEPT)

target prot opt source destination

fail2ban-SSH tcp--anywhere anywhere tcp dpt:ssh

fail2ban-SSH tcp--anywhere anywhere tcp dpt:ssh

ACCEPT all--anywhere anywhere

ACCEPT all--anywhere anywhere state RELATED,ESTABLISHED

ACCEPT tcp--anywhere anywhere state NEWtcp dpt:ssh

REJECT all--anywhere anywhere reject-with icmp-host-prohibited

It turns out that when fail2ban service starts, it inserts the fail2ban-ssh rule at the top of your iptables rules; so if you did save of your iptable rules with the fail2ban-ssh rule already inserted, iptables loads its default rules (with fail2ban-ssh in it) and then fail2ban adds it again when it starts.

To fix this, I deleted the fail2ban-ssh rules from iptables and saved those rules; now when my server boots iptables loads without the fail2ban-ssh rule and fail2ban adds it when it starts.